palpitation vs quivering

palpitation

noun
  • An abnormal beating of the heart that may be perceived by the patient, a result of excitement, exertion, or illness. 

quivering

noun
  • A motion by which something quivers or trembles. 

adj
  • shaking, shivering 

How often have the words palpitation and quivering occurred in a corpus of books? (source: Google Ngram Viewer )